This invention relates in general to static seals, and more particularly to static seals with sealing beads and fastener holes therethrough.
Static seals, also called gaskets, are often employed to seal around a perimeter of an opening, through hole, etc. Often times fastener holes are employed to hold a member against the seal or some other member on the opposite side of the seal. Also, it is common to have sealing beads extending from the surface to be sealed. The sealing beads create a localized area of high sealing force along the peaks of the beads.
A concern arises, however, when fastener holes are required to be located in close proximity to a bead—particularly when the fastener extends through a flange area that is outside of the area to be sealed. The torque on the fasteners, which may be needed to create the sealing force or for other reasons, may cause the member against which the seal is mating to bend about the sealing beads. This is particularly true for gaskets that are sealed with a relatively high clamping load relative to the thickness of one or both flanges to be sealed.
An example of such a prior art arrangement is illustrated in FIG. 9. A gasket 10 is employed to mount and seal against a member 12, with fasteners 14 securing the two together and creating the sealing force against seal bead 16. The seal bead 16 extends around the perimeter of an area 18 to be sealed. However, with the fasteners 14 through the flanges outside of the sealing bead 16, the member 12 has a tendency to bend. This bending may, in fact, create a leak path, thus making the gasket 10 ineffective. In an attempt to avoid this concern, some have tried adding grommets about each fastener, but this increases the number of parts in the assembly and adds to the complexity of assembling the gasket to the member.
Thus, it is desirable to provide a static seal that will allow for fasteners being located near sealing beads, while preventing flange bending that may lead to an ineffective seal between the seal and the member against which it is sealing.